Sheet-metal bending press



R. F. GloRbANo SHEET-METAL BENDING PRESS Nov. 7, 1961 2 Sheets-Sheet 1 ANG QHH D\ I. 9 & QT

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INVENTOR: R QQ I Fran 10 I": Gian/an.

a Q i--- m Nov. 7, 1961 R. F. GIORDANO 3,007,508

SHEET-METAL BENDING PRESS File d Sept. 5, 1956 2 Sheets-Sheet'Z 1 N VEN'T'OR I Roger Frans o "s Gin-Ja evzhu'czwdm nited States 3,007,508 SHEET-METAL BENDDIG PRESS Roger Francois Giordano, 1 Rue Michel Voisin, Sceaux, France, assignor of one-half to Promecam, Saint-Denis (Seine), France Filed Sept. 5, 1956, Ser. No. 608,152 Claims priority, application France Sept. 5, 1955 9 Claims. Cl. 153-21) This invention relates to improvements in presses of the type for bending sheet metal stock and the like. These presses comprise as a rule a movable bottom bolster controlled by hydraulic cylinders and adapted to carry the bending tools or dies, and a fixed upper bending beam or bolster carrying the bending punches.

Hitherto known presses of this general type are generally controlled by two hydraulic cylinders located on either side of the movable bottom bolster and the latter is guided laterally on the machine frame. This arrangement is inconvenient in that, due to the considerable pressures exerted on the bolsters during the bending operations the bending tools tend to sag downwards, in the case of tools carried by the bottom bolster, and upwards in the case of tools carried by the upper bolster, so that as the deformations add to each other a relatively great sag develops along the press axis. It is evident that the resulting bending is defective.

On the other hand, the lateral guiding of the movable bolster is not always satisfactory and reliable.

It is an essential object of this invention to avoid shortcomings by controlling the movements of the movable bolster by means of a central hydraulic cylinder coincident with the axis of the machine and using the cylinder body for guiding the bolster.

On the other hand, it is another object of the invention to provide a safety device incorporated in the aforesaid bolster guiding arrangement and adapted to limit any strain likely to arise from a work effected with a certain amount of overhang relative to the press axis.

Other features and advantages of this invention will appear as the following description proceeds with reference to the attached drawings forming part of this specification and illustrating diagrammatically by way of example an embodiment thereof, it being understood that many modificationsmay be brought thereto without departing from the spirit and scope of the invention as set forth in the appended claims.

In the drawings:

FIG. 1 is a front view of the improved press, with a cover plate removed to more clearly shown the press;

FIG. 2 is a side view of the press shown in FIG. 1;

FIG. 3 is a partial sectional view taken along the lines III-III of FIG. 1, viewed in the direction of the arrow and drawn to an enlarged scale; and

FIG. 4 is an enlarged partly sectional front view of a detail of the press shown in FIG. 1, drawn to substantially the same scale as FIG. 3, the section being taken along the lines IVIV of FIG. 3.

Referring first to FIG. 1, the bending press for sheet metal stock which is shown therein comprises a movable bottom bolster or movable press plate 50 controlled by a hydraulic jack 6 disposed centrally of the press and including a jack cylinder 46 and a piston 39 slidingly arranged therein. This bolster 50 is guided at its lower portion by the body or cylinder 46 of the hydraulic jack and at its upper portion by a guide member 4 aligned with the axis of the jack and rigid with the press frame or support 1. The guide member 4 may also consist of the body of another hydraulic jack arranged coaxially with jack 6 and acting on the bolster 50. The reference numeral designates the fixed press plate or upper bolster of the press.

ice

In the embodiment illustrated in thedrawings the bolster or movable press plate 50 is guided laterally preferably by rolling means or movable guide means applied on the stationary guiding member (hydraulic cylinder 46 5 and/ or guide means 4 in axial alignment with the cylinder 46) through a pre-stressed resilient device so that the movable guide means may yield laterally when the stress applied to the movable guide means exceeds the prestressing of the aforesaid resilient device.

As shown in FIGS. 1 and 3 of the drawings the lateral guiding of the bolster 50 include two pairs of roller bearings 51, 52, each pair turnably mounted on a common shaft 53. These bearings engage the body 46 of the hydraulic cylinder with a constant initial force through the device described hereunder.

The same applies to the additional guiding means positioned coaxially and above the cylinder, when such guiding means are provided.

'The shaft 53 has two flat surfaces 55 and 56 formed thereon to permit its insertion in a cutout formed in member 57 acting as a supporting and guiding member. This member 57 is rigidly connected to the bolster 50, as shown in FIG. 4. The shaft 53 has a notch 58 formed in its middle and this notch is engaged by the knife-shaped extremity of a rod 5 which urges the roller-bearings 51 and 52 against the cylinder body 46. On this rod 59 are stacked a plurality of spring washers 69 disposed between a collar 59' formed adjacent the knife-edge shaped end of the rod 59 and a member 60 secured to the bolster 50. The spring washers 69 are pro-stressed by means of the nut 61 threaded on the other end of the rod 59. By screwing the nut in or out the pre-stressing of the spring washers may be modified at will; in other words, the prestressing applied to the guiding means may be adjusted to the desired value.

As a result, whatever side stresses may be applied to the bolster 59 (FIG. 1) on account of Want of balance between the thrusts F1, F2 acting thereon during the guiding, the latter will remain perfectly safe as long as the stress is inferior to the pre-stress applied to the spring washers.

This pre-stressing may be adjusted to the value most consistent with the operation and proper guiding of the bending press concerned.

With the arrangement described hereinabove, the lateral adjustment of the working bolster is greatly facilitated. The same applies to the lubrication of the guiding members.

The movement of the end portion of rod 59 may be taken advantage of when the stress applied to the guiding means exceeds the predetermined strain limit to close a contact 62 adapted to de-energize the electromotor of the machine thereby increasing the safety of its operation.

Rollers '74 mounted on the press frame 1 in any convenient manner and engaging opposite faces of the movable press plate 50, as best shown in FIG. 2, are provided for guiding the movable press plate during its movement in a plane.

The press includes further control means consisting, for example, of a mechanical linkage in a form of a threaded rod 44 which is adapted to be rotated by means of a hand wheel 45. A nut 43 is engaged by the threaded rod 44 to be moved in axial direction along the rod, and a bell crank lever 42 turnably mounted on the press frame 1 is connected to the nut 43 and the free end of the bell crank lever 42 is adapted to engage a rod 41, controlling in turn a spring loaded ball valve 4% mounted in the piston 39 of the hydraulic cylinder 46. It will be readily understood from the schematic illustration of the arrangement in FIG. 1 that by properly rotating the hand wheel 45 the valve 40 may be unseated to discontinue the further upward movement of the piston 39 at a preselected piston position,

What I claim is:

l. A bending press comprising, in combination, a support; a press plate fixedly mounted on said support and having an elongated edge face extending in substantially horizontal direction; a movable press plate having an elongated edge face facing said elongated edge face of said stationary press plate and being arranged for movement in a direction substantially normal to said edge face thereof toward and away from said edge face of said stationary press plate; moving means including a forcetransmitting member extending in the direction of a line passing substantially normal to said edge face of said movable press plate through the center thereof and engaging with one end thereof said movable press plate only in the center region thereof for moving said movable press plate in a direction toward and away from said stationary pres plate; stationary guide means fixed to said support, extending in the direction of said line and being located in the region thereof spaced from the lateral ends of said movable press plate; and movable guide means carried by said movable press plate and cooperating with said stationary guide means for guiding said movable press plate during the movement thereof while permitting slight tilting movement of said movable press plate within its plane under the action of unequal forces acting on said edge face thereof.

2. A bending press comprising, in combination, a support; a press plate fixedly mounted on said support and having an elongated edge face extending in substantially horizontal direction; a movable press plate having an elongated edge face facing said elongated edge face of said stationary press plate and being arranged for movement in a direction substantially normal to said edge face thereof toward and away from said edge face of said stationary press plate; moving means including a forcetransmitting member extending in the direction of a line passing substantially normal to said edge face of said movable press plate through the center thereof and engaging with one end thereof said movable press plate only in the center region thereof for moving said movable press plate in a direction toward and away from said stationary press plate; stationary guide means fixed to said support and having a pair of guide faces eXtending substantially parallel to said line, substantially equally spaced therefrom, said guide faces being spaced from each other a distance being only a fraction of the length of said edge face of said movable press plate; and movable guide means carried by said movable press plate and cooperating with said guide faces of said stationary guide means for guiding said movable press plate during the movement thereof while permitting slight tilting movement of said movable press plate within its plane under the action of unequal forces acting on said edge face thereof.

3. A bending press comprising, in combination, a support; a press plate fixedly mounted on said support and having an elongated edge face extending in substantially horizontal direction; a movable press plate having an elongated edge face facing said elongated edge face of said stationary press plate and being arranged for movement in a direction substantially normal to said edge face thereof toward and away from said edge face of said stationary press plate; hydraulic moving means including a cylinder fastened to said support, and a force-transmitting member extending in the direction of a line passing substantially normal to said edge face of said movable press plate through the center thereof and engaging with one end thereof said movable press plate only in the center region thereof for moving said movable press plate in a direction toward and away from said stationary press plate; stationary guide means fixed to said support, and having a pair of guide faces formed on the outer surface of said cylinder and extending substantially parallel to said line, substantially equally spaced therefrom, said guide faces being spaced from each other a distance being only a fraction of the length of said edge face of said movable press plate; and movable guide means carried by said movable press plate and cooperating with said guide faces of said stationary guide means for guiding said movable press plate during the movement thereof while permitting slight tilting movement of said movable press plate within its plane under the action of unequal forces acting on said edge face thereof.

4. A bending press comprising, in combination, a support; a press plate fixedly mounted on said support and having an elongated edge face extending in substantially horizontal direction; a movable press plate having an elongated edge face facing said elongated edge face of said stationary press plate and being arranged for movement in a direction substantially normal to said edge face thereof toward and away from said edge face of said stationary press plate; hydraulic moving means including a cylinder fastened to said support, a piston movable in said cylinder, and a piston rod extending in direction of a line substantially normal to said edge face of said movable press plate through the center thereof and passing through an opening in a top wall of said cylinder, said piston rod abutting with one end thereof against said movable press plate only in the center region thereof for moving said movable press plate in a direction toward and away from said stationary press plate; stationary guide means fixed to said support and having a pair of guide faces formed on the outer surface of said cylinder and extending substantially parallel to said line, substantially equally spaced therefrom, said guide faces being spaced from each other a distance being only a fraction of the length of said edge face of said movable press plate; and movable guide means carried by said movable press plate and cooperating with said guide faces of said stationary guide means for guiding said movable press plate during the movement thereof while permitting slight tilting 'movement of said movable press plate within its plane under the action of unequal forces acting on said edge face thereof.

5. A bending press comprising, in combination, a support; a press plate fixedly mounted on said support and having an elongated edge face extending in substantially horizontal direction; a movable press plate having an elongated edge face facing said elongated edge face of said stationary press plate and being arranged for movement in a direction substantially normal to said edge face thereof toward and away from said edge face of said stationary press plate; hydraulic moving means including a cylinder fastened to said support, and a force-transmitting member extending in the direction of a line passing substantially normal to said edge face of said movable press plate through the center thereof and engaging with one end thereof said movable press plate only in the center region thereof for moving said movable press plate in a direction toward and away from said stationary press plate; stationary guide means fixed to said support and having a pair of guide faces formed in the outer surface of said cylinder and extending substantially parallel to said line, substantially equally spaced therefrom, said guide faces being spaced from each other a distance being only a fraction of the length of said edge face of said movable press plate; second guide means fixed to said support coaxial with said cylinder and spaced therefrom in axial direction, said guide means having also a pair of guide faces extending substantially parallel to said line, substantially equally spaced therefrom, said guide faces being also spaced from each other a distance being only a fraction of the length of said edge face of said movable press plate; and movable guide means carried by said movable press plate and cooperating with said guide faces of said cylinder and said guide faces of said second guide means for guiding said movable press plate during the movement thereof while permitting slight tilting movement of said movable press plate within its plane under the action of unequal forces acting on said edge face thereof.

6. A bending press comprising, in combination, a support; a press plate fixedly mounted on said support and having an elongated edge face extending in substantially horizontal direction; a movable press plate having an elongated edge face facing said elongated edge face of said stationary press plate and being arranged for movement in a direction substantially normal to said edge face thereof toward and away from said edge face of said stationary press plate; moving means including a forcetransmitting member extending in the direction of a line passing substantially normal to said edge face of said movable press plate through the center thereof and engaging with one end thereof said movable press plate only in the center region thereof for moving said movable press plate in a direction toward and away from said stationary press plate; stationary guide means fixed to said support and having a pair of guide faces extending substantially parallel to said line, substantially equally spaced therefrom, said guide faces being spaced from each other a distance being only a fraction of the length of said edge face of said movable press plate; movable roller guide means mounted on said movable press plate for move ment toward and away from said guide faces, respectively, and cooperating with said guide faces of said stationary guide means for guiding said movable press plate during the movement thereof While permitting slight tilting movement of said movable press plate within its plane under the action of unequal forces acting on said edge face thereof; and pre-stressed resilient means operatively connected to said movable press plate and said movable roller guide means and tending to press said roller guide means toward said guide faces to counteract til-ting of said movable press plate.

7. A bending press comprising, in combination, a support; a press plate fixedly mounted on said support and having an elongated edge face extending in substantially horizontal direction; a movable press plate having an elongated edge face facing said elongated edge face of said stationary press plate and being arranged for movement in a direction substantially normal to said edge face thereof toward and away from said edge face of said stationary press plate; moving means including a forcetransmitting member extending in the direction of a line passing substantially normal to said edge face of said movable press plate through the center theerof and engaging with one end thereof said movable press plate only in the center region thereof for moving said movable press plate in a direction toward and away from said stationary press plate; stationary guide means fixed to said support and having a pair of guide faces extending substantially parallel to said line, substantially equally spaced therefrom, said guide faces being spaced from each other a distance being only a fraction of the length of said edge face of said movable press plate; movable roller guide means mounted on said movable press plate for movement toward and away from said guide faces, respectively, and cooperating with said guide faces of said stationary guide means for guiding said movable press plate during the movement thereof while permitting slight tilting movement of said movable press plate within its plane under the action of unequal forces acting on said edge face thereof; pro-stressed resilient means operatively connected to said movable press plate and said movable roller guide means and tending to press said roller guide means toward said guide faces to counteract tilting of said movable press plate; and adjustable means for adjusting the pre-stressing of said resilient means.

8. A bending press as defined in claim 6 in which said resilient means are formed by a plurality of spring washers.

9. A bending press comprising, in combination, a support; a press plate fixedly mounted on said support and having an elongated edge face extending in substantially horizontal direction; a movable press plate having an elongated edge face facing said elongated edge face of said stationary press plate and being arranged for movement is a direction substantially normal to said edge face thereof toward and away from said edge face of said stationary press plate; moving means including a forcetransmitting member extending in the direction of a line passing substantially normal to said edge face of said movable press plate through the center thereof and engaging With one end thereof said movable press plate only in the center region thereof for moving said movable press plate in a direction toward and away from said stationary press plate; stationary guide means fixed to said support and having a pair of guide faces extending substantially parallel to said line, substantially equally spaced therefrom, said guide faces being spaced from each other a distance being only a fraction of the length of said edge face of said movable press plate; movable roller guide means mounted on said movable press plate for movable toward and away from said guide faces, respectively, and cooperating with said guide faces of said stationary guide means for guiding said movable press plate during the movement thereof while permit-ting slight tilting movement of said movable press plate within its plane under the action of unequal forces acting on said edge face thereof; pre-stressed resilient means oper-atively connected to said movable press plate and said movable roller guide means and tending to press said roller guide means toward said guide faces to counteract tilting of said movable press plate; adjustable means for adjusting the pre-stressing of said resilient means; and means cooperating with said adjustable means for stopping the press whenever excessive unequal forces act on said edge face of said movable press plate and said resilient means are thereby stressed beyond a predetermined limit.

References Cited in the file of this patent UNITED STATES PATENTS 1,354,446 Deininger Sept. 28, 1920 2,133,477 Schade Oct. 18, 1938 2,230,839 Hulsebos Feb. 4, 1941 2,286,721 Ernst June 16, 1942 2,377,007 Hess May 29, 1945 FOREIGN PATENTS 667,323 Great Britain Feb. 27, 1952 

